In many areas of daily life, ventilation of textiles or objects is desired to ensure adequate air circulation. Therefore, jackets or shoes are usually provided at least partially with substances which are air permeable so as to ensure a good exchange of air and moisture. If air circulation is not ensured, an accumulation of moisture often develops, in some cases even leading to the development of water of condensation. Therefore, various inserts have been developed to allow ventilation of objects made of textile materials, for example. The corresponding objects are often provided with openings which are covered with only an air-permeable fabric. The disadvantage of such openings is that they are not watertight and therefore water may be admitted from the outside. For clothing or shoes, coverings which are stretched mechanically over the ventilation opening are often provided.
In addition, various textile materials have been developed that make it possible to control the permeability of the textile material for water and moisture in a targeted manner. Water-vapor-permeable materials such as microfibers and/or membranes allow a low water vapor transport but do not allow circulation of air. A flat textile sheeting has been described accordingly in EP 1 054 095 A2, in which the material is stretched or shrunk as a function of temperature, thereby opening or closing the venting openings. However, this textile sheeting material can be used only in certain areas, where opening and closing are to be controlled by fluctuations in temperature.
US 2005/0249917 A1 discloses a membrane structure which allows targeted regulation of permeability as a function of ambient conditions. This membrane structure is used for protective clothing, for example, in which water vapor is to be transported out of the interior of the clothing, but hazardous liquids or gases should not penetrate into the interior. The membrane layer described here consists of two membranes whose positions relative to one another are shifted with a certain prompting. Accurate positioning of the membranes relative to one another in the manufacturing process is necessary for the functionality of the membrane system. Furthermore, a source of force, e.g., based on electric power, must be integrated into the membrane system, allowing displacement of the membranes relative to one another.
From the hygiene field, so-called superabsorbers capable of absorbing large quantities of water and swelling up in the process are known. The water uptake is reversible, so the water is released back into the environment when ambient humidity is lower. These absorber fleeces are used, for example, in diapers, items of feminine hygiene and in the construction industry. However, these absorber fleeces cannot be used for the clothing industry, for example, because they would not guarantee adequate comfort in wearing. A jacket provided with this absorber fleece would swell up greatly in the areas furnished with the absorber and would therefore increase in weight and would also release moisture to the underlying clothing, for example, by means of a resulting moisture bridge on coming in contact with other layers. Furthermore, the nonwoven materials are very sensitive to mechanical damage and even an impact against the location provided with absorber nonwoven could lead to damage and cause the absorber to swell out of the nonwoven. Furthermore, these substances are not waterproof because water not bound by the absorber seeps through between the absorber beads.